Matrix Ready - Keithley 707A Instruction Manual

Operation
Falling
Edge
I
TTLHigh
(3.4V Typical
TTL Low
(
0.25V
Typical
SOOnsec
Minimum
A. Falling
edge
of
pulse
Rising
Edge
I
TTL
High
^
(3.4V Typical
TTL Low
' '
(
0.25V
Typical
)
SOOnsec
Minimum
4.9.3
Matrix ready
The Model 707
A provides a
TTL-compatible
signal
at
its
rear
panel
MATRIX
READY OUTPUT
jack.
The
output
BNC
jack
was shown
in
Figure 4-9.
The
MATRIX READY
signal goes
false
when
relays are switched and goes
true
at
the
end
of
the
programmed
settling
time. (As described
in
paragraph
4.
1 1,
this is
also after the relay
settling time.)
Through
a
menu
item, the unit
can be programmed
for a
high- or low-true
MATRIX
READY
signal, as
seen
in
Figure
4-1
1
.
To
select the active state of
the signal, press the
MENU
key
until the
MATRIX
RDY
item
is
displayed.
The
power-up
default display
will read:
MATRIX RDY LO
TTLHigh
—
(
3.4V
Typical
TTL Low
(0.25V Typical)
Relay
Settling
Time
+
Programmed
Settling
Time
B.
Rising
edge
of
pulse A. Matrix
ready
high
true
Figure 4-10
Sample
external trigger pulses
To
choose
the alternate external
trigger
state,
use
the
SCROLL
A
or keys, then press
ENTER.
This
action
also
exits
from
the
menu
mode.
(Pressing
CANCEL
instead
of
ENTER
returns external
trigger
to
its
previous
state
and
the
Model 707A
remains
in
menu
mode.)
TTL
High
(3.4V Typical
TTL Low
"
(0.25V Typical)
Relay
Settling
Time +
Programmed
Settling
Time
8. Matrix
ready low
true
In master/slave
configurations, only the
EXTERNAL
TRIG-
GER
INPUT
port of the master
unit
is
active.
Sample
matrix ready pulses
See paragraph
4.
1 1
for
more
information on
triggering the
Model 707A.
To
choose
the other active
state,
use
the
SCROLL
A
or
T
keys, then press
ENTER.
This
action also
exits
from
the
menu
mode.
(Pressing
CANCEL
instead
of
ENTER
returns
matrix ready
to
its
previous
state
and
the
Model 707A
remains
in
menu
mode.)
In
master/slave configurations,
the
MATRIX READY
sig-
nals
of
all
units function, but only
that of
the
master
is to
be
considered
accurate.
4-15